Percussive type electric musical instrument



June 19, 1962 s. l.. KRAUSS ET AL PERCUssIvE TIPE ELECTRIC MUSICAL INSTRUMENT Filed Aug. 8. 1957 5 Sheets-Sheet 1 M EN .MS Q

INVENTORS Serge J'.. Krauss Char/es J. Tennes mee @M June 19, 1962 s. l.. KRAUSS ET AL 3,039,347

PERCUSSIVE TYPE ELECTRIC MUSICAL INSTRUMENT Filed Aug. 8, 1957 5 sheets-sheet 2 Ays INVENTORS Serge L. Krauss Char/els J Tennes wkw/v t; m

w we@ mc@ ESQ v NSS @nl Vv. .QH In.

June 19, 1962 s. l.. KRAuss ET AL 3,039,347

PERCUSSIVE TYPE ELECTRIC MUSICAL INSTRUMENT www @M Ahys.

United States :Patent O 3,039,347 Y PERCUSSIVE TYPE ELECTRIC MUSICAL INSTRUMENT Serge L. Krauss and Charles J. Tenues, Elkhart, Ind.,

assignors to C. G. Conn, Ltd., Elkhart, Ind., a corporation of Indiana Filed Aug. 8, 1957, Ser. No. 677,041

1,8 Claims. (CLM-1.26)

This invention relates generally to electric musical instruments, and more particularly to percussion systems for modifying the characteristics of the tones produced by electric organs.

In electric organs and other electric musical instruments, it is desirable to simulate the characteristics of many instruments. One problem is to provide percussive bursts of sound to simulate plucked strings, bells, and other percusssion instruments. Percussion systems known hitherto have either been very expensive or, when less eX-v pensive, have been very limitedin performance.

A further object of the invention is to provide a per- A cussion system for an*y electric organ serving to cause repetitive bursts of tone of the organ to duplicate the sounds of. struck bar and plucked string instruments.

Still another object of the invention is to provide a percussion system for an electric musical instrument .for providing repetitive Vbursts of sound with a predetermined audible level between the bursts.

A stillV further object is to provide repetitive bursts of sound which are interspersed with sound of a different tone to simulate the Xylophone, marimba, and vibraharp.

Yet another object of the invention is to provide a percussion system for an electric organ in which repetitive bursts of sound are created with decay time -for the bursts varying from a very short time to several seconds to produce sounds of plucked string and struck bar instruments as well as the sounds of other percussion instruments.

A feature of the invention is the provision of `an electric musical instrument having la percussion system which is selectively connected in and out of the signal transmission pathof tone generators of the instrument and operates to produce bursts of signal when actuated by an electric control circuit connected to the keying circuit ofthe instrument without mechanical modification of the keys or sacriiice of any of their functions. A diode in the keying circuit provides a voltage drop which is amplified to actuate the percussion system.

Another feature of the invention is the provision in an electric musical instrument of a modulator operable by keys of the instrument for producing bursts of sound from any of several tone generators of the instrument, with,

3,039,347v Patented June `19, 1962 ice A still further yfeature of the invention is the provision of an electric organ including a plurality of key-actuated tone generators and a control circuit actuated by one of the keys to cause a modulator circuit to gate the output of the generatorsl supplying Ia sound reproducer to produce a percussive burstof tonefrom the reproducen The control circuit may provide cyclic operation (multi-vibrator) for repetitively actuating the burst-producing network of the modulator circuit when one of the keys is actuated. The repeating action may be synchronized with the tremolo generator of the organ. A selectively operable control may also be provided for producing a single burst or repeated bursts when one of the keys is touched momentarily, and the decay time of the bursts may be adjusted to produce different effects. For example, the decay time may be made short to cause the bursts of sound to duplicate the sound of a plucked string or a struck bar, or it may be set to have a Ilonger time to simulate a bell or other percussion instruments.

In the drawings:

FIG. l is a block diagram of an electric organ system y"in accordance with the invention;

FlG. 2 shows a circuit diagram of an electric organ including a percussion system forming one embodiment of the invention;

FIG. 3 shows a part of a circuit diagram of an electric rgan forming an alternate embodiment of the invention; and Y FG 4 shows a part of an organ circuit which illustrates a further embodiment of the invention.

The invention is illustrated in an electric organ and provides a percussion system which may be actuated to provide single or repetitive bursts of selected tones with either no sound between the bursts or a predetermined audible Vsound level between the bursts which may be of the same or a different tone. A decay time of several seconds may be provided `for each burst, or a short decay time to simulate a plucked string, or a struck bar, or the like may be used. The percussion system is incorporated into -an electric organ having a plurality of tone generators lwhich actuate one or more mixer sections normally transmitting the tone signals to'an amplifier driving a reproducer such as a loudspeaker. The percussion system includes acontrol circuit connected in the circuit of the fkeys of one of the keyboards of the organ, and whenever one of these keys is operated current ilows through a diode in the control circuit 'andprovides a voltage drop which actuates relay means in the control circuit. The actuation of the relay means kapplies a gating pulse to trigger a gating or modulator section in the signal transmission path.

The control circuit may includecyclic interrupting means such as a multi-vibrator or a rel-ay circuit to cause the relay means to repeatedly actuate the modulator to form repetitive bursts of the sound, thusproducing eifeets such as the sounds from a Xylophone, m-arimba, mandolin, guitar, and the like. The multi-vibrator may be selectively cut in or cut out of the circuit so that either repetitive bursts lor only a single burst of sound is produced. Also, control means for the multi-vibraton is provided which may be 4adjusted to provide different repetition rates of operations of the relay, and the modulator section may be adjusted to provide different decay times for the diiferent bursts of sound so that various percussive instruments may be simulated. The modulator circuit may be adjustedso that, between the tone burst, the tone level may be either zero or at a chosen audible level. The system may also provide a diferent related tone between the bursts of the selected tone to better simulate certain instruments. A steel guitar or novelty effect may also be provided in the organ by use of the percussion system. This is accomplished `by altering the bias on `the tone generator to detune the same at the start of the burst, with the generator being allowed to resume its normal pitch While the tone burst is decayed.

FIG. 1 shows lthe basic systemof the organ in block diagram, and illustrates an organ having two keyboards, the swell keyboard 11 and the great keyboard 16. Tone generators 12 are lactuated by both keyboards and a tremolo generator 15 provides low frequency signals to Y plied. The percussion modulator. 3S acts on the voices applied therethrough, and may be bypassed by the'switch 38. A relay 40 is provided for imparting a sharp attack characteristic and this maybe by-passed by switch 48. The circuit 41 which control the percussion modulator is actuated by the diode 44 connected to the swell keyboard 11. The control circuit may provide a repeating or cyclic `action which may be synchronized with the tremolo generator 15 through action of the switch 39: The output ofthe percussion modulator may be combined with the output from the generators associated with the great keyboard and with signals fromthe swell keyboard which are by-passed about the percussion modulator.- The combined signals are* applied to the expression pedal 97, which controls the level of signals applied to the amplilier 36. The amplifier 36 raises `the level of the signals to that required to drive the loudspeaker 37.

FIG. 2 shows the electric organ circuit more Particularly, with keysy 11, 16, and 17 of various keyboards of the organ being connected to a tone generator 12 which may be of a known type. A plurality of such .tone generators willbe provided .to furnish the diiierent tones to be produced. The tone generators each include a bias network 13 to which is connected a tremolo section 15 of known construction and operation. A flute output rfrom each of the tone generators 12 is applied through conductor 21 to a mixer section 22, and, similarly, a pulse or string output is coupled by a lead 24 from the tone generators 12 to the mixer` section 22. The mixer section 22 produces various combinations of flute and Vstring tones and is controlled by various organ stops shown schematically at 26.

The output of the mixer is transmitted to a tone control section 31 ofa known type, and the output thereof is coupled by a capacitor 32 to a control grid 33 of tube 34 forming apart of a gating or modulator circuit 35. 'li he tube '34 is connected in a cathode follower circuit and applies the tone signals to transformer 63. The transformer 63 provides a balanced input to push-pull tubes S4 and 35 which Iare gated to selectively pass the signals as will be described in more detail. The output ot the tubes S4 and 85 is applied through transformer 92 to ampli-Iier 36. The modulator circuit 35 may be by-passed by operation of switch contacts 38 so that it is selectively connected in and out of the signal transmission path from the tone control 31 to the -amplier 36 which drives a loudspeaker reproducer 37 ofthe organ.

The modulator circuit is controlled by a control lcircuit 41 having a lead 42 connected to the key 11 of one keyboard of the electric organ. When the key 11 is depressed to actuate the .tone generator 12, B+ voltage is supplied to the tone generator from a terminal 4S through the impedance device formed by diode 44, the

terminal 45 being connected to a positive direct current `potential source which may provide 75 volts. lThe flow of current through the diode 44 causes a drop of voltage to occur across the diode, and this voltage drop reduces p 4 K p the conductivity of a control tube 47. Tube 46 is associated with the control tube 47 to compensate for power supplyvoltage vari-ations. l

The tube 46 establishes the bias for the tube 47 with reference to the 75 volt positive supply. This prevents the normal variations in the supply potential from being impressed on the stage including tube 47 as a control signal. With no key operated, the tube 47. is held at zero bias by the bleeder resistor 49 trom the V250 volt source. When a note is keyed, the oscillator current flowing through ythe diode 44 in series between the 7-5 n volt supply and the keying bus causesV a drop of ap` proximately .3 volt in the diode.` The voltage difference across the diode resulting from actuation of akey is the Y normal bias of the tube 46 plus the .3 volt drop, or approximately 2.0 volts total, which is irnpressedon the grid of the tube 47. When the conductivity of tube 47 is so reduced, its plate voltage rises to increase the voltage on a signal grid V51 of a vacuum tube 52 to allow the tube 52 to conduct. When the tube `52 is made conductive, a relay 53 in the plate circuit of the tube is operated to open contacts 54 and close contacts 55 inthe modulator circuit 35.

The tubes 84 and 85 inthe modulator circuit are Vnormally cut oif by the positive bias applied to the cathodes thereof through the voltage divider including resistors 77, 81, 32, 83, 88, and 89. Resistor 77 is variable so that the cut-ott bias may be adjusted. The open ing of contacts 54 of the modulator circiut 35 connects series resistor Gland capacitor 62 to a` center tap on the secondary of transformer 63 in the control Igrid circuits of tubes S4 and d5. Thistransmits a positive pulse tok the control grids of tubes 84 and 85 from the voltagedivider mentioned above, which overcomes the cut-ott bias on the tubes 84 and 85. This pulse lasts until the capacitor 62 charges up through resistors V61 and 72, and causes a burst of tone signal to` be transmitted throughtransformer 92 and potentiometer 97 to the output amplitier 36. The potentiometer 97 may be controlled by the expression pedal of the organ to thereby control the audio volume ofthe output. The duration of the resulting burst of sound is controlled by the resistance-capacitance network, which may be adjusted between sort bursts and longer bursts by operation of switch 74. Switch or tablet 74 connects resistor 73 in parallel with resistor 72 to decrease the resistance ofthe charging path of capacitor so that a short burst is provided when the switch is closed,`

and a longer burst is providedwhen the switch 74 is open.

lThe push-pull circuit of the modulator 35 is balanced by the cathode of tube 84 being connected to the midpoint of resistor 83, and the cathode of tube being connected to the slider of the potentiometer 82. The resistor 78 may be connected by a tablet switch. 79 in the bias circuits of the tubes 84 and 85' in shunt with resistor 77 to reduce the bias to a point at which the tubes are not completely cut oilE and a predetermined audible tone level is produced between the bursts of sound. Resistor 78 is adjustable to set this level as desired. When tablet 79 is open, the bias is increased so that there is no sound Vpi'oducing signal from the modulator 35 during intervals between the percussive bursts.

The tube 52 of the control circuit 41 and a tube 102 form a free running multi-vibrator circuit which includes j a potentiometer parallelling the relay 53. A slider on the potentiometer is connected through resistor 106 and capacitor 1437 to the control grid of tube 102. The grid is biased by resistor 16S and the cathode isA grounded i.

biased by resistor 110. The dwell of the relay 53 isdeter mined by the value of the resistor 104, and in one instance, the dwell time was slightly lessrthan half the time .of one cycle of the multi-vibrator circuit. Also, the

time. The control of dwelltime and repetition ratevare substantially independent of each other. For each cycle of the multi-vibrator circuit, the relay S3 is energized and deenergized, and a burst of sound is produced. p

A repeat tablet or stop 191 is provided in shunt with the resistor S, and when the tablet 1111 is open, the multivibrator is free running to alternately cause the relay 53 to pull up and drop out. The multi-vibrator will lcontinue to run as long as one of the keys 11 is depressed. When the tablet 1M is closed, the gridv resistor la is shunted and the tube 192 is kept inoperative so that the tube 52 is kept conductive as long as one of the keys 11 is closed and only a single burst of tone is produced.

Switch 112 is mechanically connected to switch contacts 38 and may be actuated by a single control or tablet. To cut out the percussion eiiect from the organ, the tablet 112 and contacts 3S are closed. The switch 112 connects grid 51 and clamping anodes 119 of tube 192 to ground to cut off the tube 52 and prevent operation of the relay 53. The anodes 119 of tube 102 connected to the signal grid 51 of tube 52 act as a clamp during operation of the multivibrator' when stop 112 is open. A regulator glow-lamp 117 absorbs the equivalent of the relay current when tube 52 is cut ofi to prevent load tiuctuation from being impressed on the power supply. As previously stated the contacts 38 apply signals from the tone control section 31 past the modulator circuit 35 to the ampliier 36.

The signal may be applied from the transformer 92 to the expression pedal potentiometer 97 through a switch 9i). This switch is coupled to a switch 91 so that when switch 90 is opened, switchl is closed. Switch 91 is in the energizing circuit for relay 93, being connected in series with contacts 94 on relay 53. Accordingly, when switch 90 is opened and switch 91 is closed, operation of the relay l53 will close contacts 94 to cause operation of the relay 93. This will close contacts 95 which connects the transformer 92 to the potentiometer 97 of the expression pedal. The relay 95 is a slow to operate relay so that the signal will not be applied to the expression pedal potentiometer 97 for an interval provided by this relay. Accordingly, operation of this relay will provide what may be considered a sharp attack since the signal will be built up -in the system before 'itis applied to the output amplier and speaker.

As previously stated, the repeat action of the percussion system may be synchronized with the tremolo of the organ.l The circuit for accomplishing this is shown-in FG. 2, with the conductor 114 applying oscillations from the tremolo section 15 through resistor 115, condenser 116, and switch 39 to the grid of tube 102. This synchro'- nizes the multi-vibratorrformed by tubes 52 and 162, with the oscillations from the tremolo section 15.

In the circuit of FG. 2', the line 42 to the control circuit is connected only to the keys 11 on one manual. These may be the keys on the swell manual, with the keys 16 being on the great manual and the keys 17 on the pedal board. It is quite easy toV provide more elaborate or unique features such as percussing families of voices or even individual voices and exclude the remainder from this effect. Keying any of the swell manual keys gates the modulator for a tone burst. A swell to great intermanual coupler provides a means of keying the swell manual generators from the great manual keys without gating the modulator. Then when any key is pressed in the swell manual the tones from the generators being keyed by the great manual keys (Via the intermanual coupler) will be percussed simultaneously. In this manner a group of keys can be pressed on the great manual for a chime or chord eti-ect and a simultaneous tone burst can be triggered by the same or another note keyed on the swell manual. A sharper tone burst is provided in this manner because the generators are already up to ampliture beforethe modulator is gated. Both hands may be used on the great manual with only one nger raised to press a swell manual key for gating the tones. The chord organ effect so produced is very striking, for one finger f playing on the swell manual will produce percussed chords played on the great manual.

InFlG. 3, there is shown a secondpernbodiment of the invention in which the repeating or cyclic action is provided by a relay. The modulator 35 is connected between the tone control 31 and amplifier 36 as in FIG. 1. The control circuit 141 includes tubes 46 and 47 as in FIG. l and actuates the modulator 35 to cause bursts of sound whenever one of keys 11 is depressed to actuate a tone generator 12. A switch 145, in its actuated position (dotted), connects tubes 46 and 47'operatively to keys 11 and connects tone control section 3 1 to modulator '35, breaking the direct connection of the tone control section 31 and the amplifier 36. Then when key 11 of a tone generator is closed, the tube 142 is made conductive to provide current ilow through closed contacts 154 to the relay .winding of the relay 147. This energizes the relay to break contacts 54 and 153 and make contacts 55. This connects resistor `61 and capacitor 62 to the modulator 35 as described in connection with FIG. 1 to actuate the modulator to cause a burst of tone.

To provide a repeating eiect, switch 154 may be moved to its dotted position to connect capacitor 146 across relay 147. Now when a key 11 is closed, the relay is energized through contacts 149 and 151 of switch 152 and through contacts 153. When -the relay operates, opening of contacts 153 cuts orf the relay 147, but it remains energized while capacitor 146 discharges and the burst of tone occurs before the relay 147 drops out. As the relay 147 drops out, it recloses contacts 153:l to reenergize itself and canse another burst of tone, assuming the key 11 is still depressed. Thus, a repetition of the sound bursts may be eiected. When the switch is moved to its Oil position (solid line), lthe tubes 46 and 47 are cut out of the key circuit, and the tone control section 31 is connected directly to the ampliiier 36, and normal playing of the organ may be effected.

The switch 152 may be operated to providea steel guitar effect in the organ. Contacts 149 and 151 in the dotted position shunt out a portion of the bias resistorvv 13 through closed contacts 153 to detune flat the tone generator oscillator 12. The contacts 154 are in the Oil position as no repetitiveetfect is provided in this condition. When the relay 147 operates, contacts 153 open so that the shunt is removed from the bias resistor and the generator resumes its normal tone. This is the tone effect provided by a steel guitar. This bias shuntng arrangement may also be provided with the circuit of FIG. 2 to produce a steel guitar effect with this circuit.

A good novelty eect may be provided by detuning the tone generator oscillator sharp. Otherwise, the circuit and operation may be exactly the same as for the steel guitar effect. Y

The following constants which have been used in the circuit of FlG. 2 are listed below merely by way of illustration and are not intended to limit the scope of the Ain- Ventron in any way.

Capacitor 32 microfarads-- .047 Tube 34 4.-- 6AU6 Capacitor 39 n microfarads 1'0 Tubes 46 and 47 12AX7 Resistor 48 megohms .56 Resistor 49 do 2.2 Resistor 50 kilohms 82 Tube 52 6AU6 Capacitor 62 microfarads-- .47 Capacitor -71 do- 0.47 Resistor 72 megohms` 3.3 Resistor 73 do 1.0 Capacitor 76 microfarads-.. 50 Resistor 77 kilohm 1 Resistor 78 ..do l Resistor S1 ohms- 68 '-174 drops out.

7 Potentiometer 82 0hms 50 Resistor 83 olims (each) 27 Tubes 84' and 8S `6AU6 Resistor 8S kilohms 10 Resistor 89 do 12.5 Resistor 96 do 7.5 Potentiometer 97 do 100 Resistor 98 megohm .l Capacitor 99 microfarads .039 rTube 162 6AV6 Resistor 1114 megohms .27 v Resistor 106 do .47 Capacitor 167 microfarads .l Resistor 168 megohms .47 Resistor 169 kilohrns 3.9 Resistor 11@ megohm l Capacitor 118 microfarads .15 Resistor 131 megohms 1.0 Resistor 132? kilohms 56 Resistor 133 ohms 1500 FIG. 4 shows a somewhat simplified percussion'arrange ment which includes the same control circuit as in the prior embodiments. When a key from the keyboard 11 is depressed, engagement will be made with one or more ofthe couplers 161i, 161, 162, 163, 164, or 165, depending upon the operation of the tablets which control the couplers. A particular generator will be actuated depending upon the key operated and the operation of the tablets. lt will be noted that couplers 161i', 163, and 16d are directly connected to the 7 5-volt keying source so that connection to these couplers upon actuation of the keys will cause operation of the tone generators Without any action in the percussion system. Couplers 161, 162, and 165 are also connected to the 75 volt keying source Vthrough the percussion control switch 166, when this switchis in its center or normal position. However, when the switch 166 is turned counterclockwise to the Xylophone position, while coupler 161 still remains connected to the 75-volt keying source, couplers 162 and 16S are disconnected therefrom. inthe clockwise or marimba position,

coupler 166 remains connected to the keying source and couplers 161 and 1,62 are disconnected therefrom.

When the switch 4166 is in the Xylophone position, coupler 162 controls the system. When a connection is made to coupler 162, the tone generator so connected is energized through the' diode 171i. This diode controls the potential to triode tube 171 in exactly the same manner as in the circuit of FIG. 2. Triode 172 serves to establish the bias on tube .171 as previously described. The voltage drop across the diode is amplified in triode 172 and causes Itube 173 to conduct to actuate the relay 174 connected in the plate circuit thereof. This opens contact 175 to break the connection to the coupler 162 and thereby denergize the tone generator connected thereto. Operation of relay 174 closes contact 176 which provides a keying voltage for the coupler 165.' Accordingly, as long as a key associated with the couplers is still operated, the tone changes from the tone produced by action of coupler. 162 to the tone produced by action of coupler 165. Since the circuit through the diode 170 and coupler 162 is broken, the tube 173 ceases to conduct and the relay 'Ihis causes contacts 175 to make the connection to the coupler 162. Therefore, a repeating intermittent change between the tones produced by coupler 162 and 165 is provided. The capacitor 177 connected to the grid of tube 173 controls the repetition interval to thereby provide the desired speed of the cyclic or intermittent operation. The regulator lamp 178 absorbs the relay current as previously described to prevent Huctuations in the load on the power supply.

When the control switch 166 is placed in the marimba position, it is the coupler 161 which is normally connected to contacts 175 andthe diode 171) by operation of a key. When the coupler 161 is rendered active, the tone associated with coupler 161 is produced, and the Voltage across the diode drops to actuate the relay 174 in the Inanner previously described. This opens contacts so that` The system of FIG. 4, as previously stated, is somewhat simpler and less expensive than that of FIGS. 2 and 3. The eiect produced, however, very closely approaches -that of certain percussion instruments. When the couplers 160 to 16S are used to provide 16', 8', 4 22/3, 2, and 13/5 tones respectively, the combination of tones from couplers 162 and 165 provides a good xylophone effect, and the combination of tones from couplers 161 and 162 provides a good marimba or vibraharp effect.

' In FIG. 4 only the energizing circuit for the tone generators is illustrated and the system for applying the tones from the generators to the mixers, expression pedal, the output amplier and the loudspeaker may be as shown in FIG. 1. In such a system the percussion modulator may be eliminated as the Ypercussion effect is obtained by interruption of theenergization of the oscillators. The` system of FIG. 4 shows the connections to .the couplers of a single key and it will be understood that the system may also be connected to couplers of other keys.

The above described electric organs are highly flexible in providing percussion tones. The tones may be very short or may be very long as selected by the organist. No

multiple contact keys are required therefor, nor are any mechanical actuating devices required to incorporate the percussion producing components into the electric organ. The organs may be adjusted merely by use of the tablets to provide repetitive bursts of either long duration or short duration to simulate the electric guitar with no tone in between bursts or with a desired tone maintained between bursts. The organs so fabricated cost very little more than organs without the percussion sys-l, tems incorporated therein, only the modulator circuit and the control circuit being required in addition to the normal components of the organ.

We claim:

1. ln an electric organ includ-ing a tone generator, a sound reproducer, a mixer operable by the tone generator vfor applying signals from the tone generator to the reproducer and a plurality of keys connected in parallel in an energizing circuit for the tone generator, the combination therewith of a modulator circuit normally blocking signals from the mixer to the reproducer and operable when actuated to apply a burst of signals from the mixer to the reproducer, and timing meanslcoupled to the energizing circuit and operable in response to current flow therein resulting from actuation of one of said keys said timing means being coupled to said modulator circuit and initiating operation of the same so that said modulator circuit operates to pass signals to the reproducer for a predetermined period of time to cause a burst of sound from the reproducer, said timing means including adjustable means for selectively controlling the duration of each burst of sound.

2. In an electric organ including a loudspeaker, an ampliier for driving the loudspeaker, an electronic tone generator, a key for applying energizing potential to the tone generator, and a mixer circuit for transmitting signals from )theV tone generator to the amplier, the combination therewith of gating means for selectively providing a burst of signalto the ampliiier, and control means operable upon actuation of the tone generator for actuating said gatingmeans, said control means including impedance means connected to the key for applying current to the voltage drop across said impedance means coupled to said gating means for actuating the same.

3. In an electric musical instrument including a loudspeaker, an ampliter for driving the loudspeaker, an electric tone generator, a key for applying energizing potential to the tone generator, and a mixer circuit for transmitting signals from the tone generator to the amplifier, the combination therewith of gating means for selectively providing a burst of signal to the amplifier, and control means coupled to said gating means and operable upon actuation of the key for actuating said gating means, said control means including diode means connected between the key and the generator and conducting the energizing current thereto, a control tube coupled to said diode means and rendered conductive in response to the voltage drop across said diode means, `and relay means coupled to said control tube and controlled thereby, said relay means being connected to said gating means for actuating the same.

4. In an electric musical instrument including a loudspeaker, an amplifier for driving the loudspeaker, an electric tone generator, supply means for providing energizing potential, a key for applying potential from the supply means to the tone generator, and a mixer circuit for transmitting signals from the tone generator to the amplifier, the combination therewith of gating means for selectively providing a burst of signal to the amplifier, and control means operable upon actuation of the key for actuating said gating means, said control means including diode means connected to the key for applying current to the for supplying energizing current to the tone generator, iirst relay means for selectively actuating said gating means, means connecting said rectifier means to said first relay means and responsive to the flow of current through said rectifier means for actuating said first relay means,

and second relay means connecting said gating means to the loudspeaker, said` second relay means being coupled to said first relay means vand including delay means causing operation of said second relay means in response to operation of said rst relay means after a time interval, so that signals are transmitted by said gating means and applied through said second relay means to the loudspeaker in response to operation of said first relay means.

8. In an electric musical instrument including a plurality of tone generators with keys for selectively operating the same, a mixer for combining signals from the tone generators and a loudspeaker for reproducing the signals produced by the tone generator, modulator means generator, a iirst electron valve connected to said diode means and responsive to the voltage drop across said diode means, means coupling said first electron valve to said gating means for actuating the same, and a second electron valve coupled to said first valve for reducing the effect on said first valve of variations in the potential of the supply means.

5. In an electric organ including a tone generator, a sound reproducer, and a key for actuating the tone generator, the combination therewith of a gating stage coupled between the generator and the sound reproducer, a resistance capacitance timingnetwork for applying an actuating pulse relay means coupled to said network and to said gating stage, said relay means having a first posii tion for coupling said network to said gating stage for actuating the sarne and a second position for removing said relay means for actuating said relay means alternately between said first position and said second position, and means operable by the key for actuating said cyclic means. f s

6. In an electric musical instrument including a plurality of tone generators with keys for selectively operating the same, a mixer for combining signals from the tone generators and a loudspeaker for reproducing the signals produced by the tone generator, the combination therewith of modulator means for coupling the mixer to the loudspeaker and including an electron discharge device, means for applying signals from the mixer to said electron device, adjustable biasing means coupled to said device for holding the same at a loW level of conductivity, means coupled to said keys and responsive to operation thereof for providing a voltage pulse, said last named means being coupled to said electron device and v applying said pulse thereto for increasing the conducsaid network from said stage, cyclic-meanscoupled to for coupling the mixer to the loudspeaker including first and second electron discharge devices connected in pus-hpull, means for applying signals from the mixer to said electron devices, biasing means coupled to said devices including switch means having a Iirst position for holding said devices cut off and a second position for holding said devices at a low level of conductivity, means coupled to said keys and responsive to operation thereof for applying a voltage pulse to said electron devices for increasing the conductivity thereof, said last named means including a timing circuit for controlling'the duration of the pulses applied thereto, said timing circuit including second switch means having a first position providing pulses of a. first duration and a second position providing pulses of a different duration.

9. An electric musical instrument including in combination, a loudspeaker, a tone generator, a key for establishing an energizing circuit to the tone generator, gating meanscoupled to said tone generator for selectively translating `signals from said generator, control means coupled to the tone generator and responsive to operation of said tone generator, said control means being coupled to said gating means for actuating the same, and adjustable bias means for said tone generator, said control means adjusting said bias means for changing the tone pitch ott the tone generator simultaneously with the transmission of signals from said generator.

l0. An electric musical instrument including in combination a plurality of tone generators for providing tone signals, a plurality of keys operable kto selectively apply current to said tone generators to actuate the same, a sound reproducer for reproducing the tone signals, gating means for selectively controlling the application of tone 'signals to said sound reproducer, and a control circuit coupled to said :gating rneans and `operating the same in response to actuation of a tone 'generator resulting from operation of one of said keys, said control circuit including impedance means connected to said keys for applying current through an actuated key to siad generators coupled thereto, and electron valve means cou-pled to said impedance means and responsive to the voltage drop thereacross, said electron valve means being coupled to said gating means for actuating the same, said gating means including first contact means -for interrupting signals from one tone generator associated with an Operated 'key land second contact means `for providing signals from a diierent tone generator operated by the same key.

l1. An electric organ including in combination, a plurality of tone generators for producing difierent tone signals and including tone generators provided as first and second groups, a plurality of keys including a group of keys each of which is associated with a tone generator of the rst group and with a -tone generator of the second group, each of said keys including switch means, a sound reproducer coupled to said tone generators for reproducing tone signals therefrom, gating'means including relay l l means having first normally closed contact means and second normally open contact means, rectifier means, an energizing circuit for said tone generators of said first group including said rectifier means and said first Contact means with the circuits to the individual tone generators being completed through said switch means of the associated keys, an energizing circuit for said generators of said second group including said second contact means with the circuits to the individual generators being completed through said switch means of the associated keys, said first contact means and said rectifier means operating to apply current to a generator or the first group in response to operation of the key associated with said generator,

u. and control means coupled to said gating means-and operable upon actuation of a tone generator for actuating said gating means, said control means including an electron valvecoupled to said rectifier means and responsive to the voltage drop across said rectifier means, said electron valve operating said relay means of said gating means to open said first contact means and cut ofi the generator of the first group and to close said second contact means and actuate the generator of said second group associated with the operated key.

l2. An electric organ including in combination, a plurality of tone generators for producing different tone signais and including tone generators provided as first and second groups, a plurality of keys including a group ol 'keys each of which is associated with a tone generator of the first group and witha tone generator of the second group, each of said keys including switch means, a sound reproducer coup-led to said tone generators for vreproducing tone signals therefrom, gating means including relay means having first normally closed contact means and second normally open contact means, rectifier means, an energizing circuit for said tone generators of said first group including said rectifier means and said vfirst contactk means with the circuits to the individual tone generators being completed through said switch means of the associated keys, an energizing circuit for said generators of said second group including said second contact means with the circuits to the individual `generators being completed through said switch means'of the associated keys, said first contact means and said rectifier means operating to yapply current to a generator of the first group in response to operation of the key associated with said generator, yand control means coupled to said gating means and operable upon actuation of a tone generator for actuating said gating means, said control means including electron valve means coupled to said rectifier means and responsive to the voltage drop across said rectifier means, said electron valve means operating said relay mea-ns of said gating means to open said first contact means and cut ofi the generator of the first group and to close said second contact means and actuate the generator of said secc-nd group associated with the operated key, whereby tone signals from said generators of said first and second groups yare alternately reproduced, said control means including means controlling the rate of alternate reproduction of the tone signals.

13. In an electric musical instrument including a tone generator, a tremolo generator selectively coupled to the tone generator, a loudspeaker, and a key for actuating the tone generator', the combination therewith of gating means coupled between the tone 4generator and the loudspeaker for controlling the application of signals `from the tone `generator to the loudspeaker, a control circuit coupled tothe key and to said gating means for applying actuating pulses to said gating means in response to actuation o-f the key, and cycling means coupled to the tremolo generator and cooperating with said control circuit for repeatedly applying actuating pulses to said gating means for actuating the same in'synchronism with the tremolo generator to provide repeating bursts of signals to the loudspeaker.

14. In an electric musical instrument including a loudlli speaker, an amplifier for driving the loudspeaker, an electric tone generator, supply means for-providing energizing potential, and a key Ifor applying potential from the supply means to the tone generator, the combination therewith of `gating means for selectively providing a burst of signals from the generator to the amplifier, and control means operable upon actuation of the key ttor actuating said gating means, said control means including impedance means connected to the key for applying energizing currentto the generator, an electron valve connected to said impedance means and responsive to the voltage drop thereacross, means coupling said electron valvel to said gating means for actuating the same, and stabilizing means coupled to said electron valveV for reducing the effect thereon of variations in the potential or the supply means.

15. ln an electric musical instrument including a plurality of tone generators with keys for selectively operating the same, a mixer for combining signals from'the tone generators, and a loudspeaker for reproducing the signals produced by the tone generators, the combination therewith of modulator means ffor coupling themixer to the loudspeaker including an electron device, means for `applying signals `from the mixer to said electron device, biasing means coupled to said electron device for holding the same at a low level of conductivity, means coupled to sai-d keys and responsive to operation thereof for providing a voltage pulse, said last named means being coupled to said electron device and applying said pulse thereto for producing tone signals, a key for actuating the tone generator, supply means `for providing positive potential, and a loudspeaker, the combination therewith of gating means coupled to the tone generator for transmitting signals therefrom to the loudspeaker, a circuit including rectifier means connecting the positive potential supply means tok the key `for supplying energizing current to the tone` generator, relay means for selectively actuating said gating means, control means including `an electron device connected to said rectifier means and responsive to the voltage thereacross, means connecting said electron device to said relay' means for actuating the same so that signals are transmitted by said gating means, said control means including feedback means coupled to said electron device for causing recurring operation thereof, and switch means for selectively activating said feedback means7 with said control means producing a single burst of signals in respouse to operation of the key when said feedback means is deactivated and a plurality of bursts of signals when said feedback means is activated. e

17. The combination of claim 2 including means selectively connecting said gating means between the mixer circuit and the amplifier, vand wherein said control means includes relay means for applying pulses to said gating means for rendering the'same operative in response to actuation of the key, and means for changing the tone produced bythe electric tone generator coupled to said relay means and operated thereby simultaneously with the transmission of signals from the tone generator by saidgating means.

18. The combination of claim 2 wherein said control means includes means for lapplyu'ng pulses to said gating means for rendering the same operative in response to actuation of the key, and bias means coupled to the tone generator for'changing the pitch thereof, said bias means being actuated by said control means to change ythe pitch References Cited in the le of this patent UNITED STATES PATENTS Hanert Nov. 10, 1942 Rienstra June 4, 1946 Kent Dec. `28, 1954 14 Anderson Jan. 14, 1958 Anderson Feb. 11, 1958 Hanert Apr. 1, 1958 Wolgast Aug. 12, 1958 Hanert Aug. 26, 1958 Hanert Dec. 15, 1959 Hanert Dec. 15, 1959 Hanert Sept. 20, 1960 

